1. Field of the Invention
The present invention relates generally to an authentication system and methodology in which items incorporating an authenticating agent as a product marker can be used to confirm the source of the items. More specifically, the authenticating agent of the present invention forms detectable free radicals upon exposure to a suitable dosage of ionizing radiation. An item can be irradiated and then subjected to spectroscopic analysis in an easy, straightforward fashion to determine whether it incorporates the marker and therefore comes from a particular source.
2. Background of the Invention
Throughout history, extensive efforts have been undertaken by manufacturers of industrial and retail goods in attempts to ensure that their goods can be readily distinguished from the goods of others. Measures used in this effort have included the use of unique product markers. Such markers have been physically observable features placed on goods (e.g., holograms, microreplicated patterns, water marks, product codes, trademarks, trade dress, and the like) or chemical authenticating agents (e.g. fluorescent materials, special inks, dyes or the like) that have unique, detectable properties which often are hidden under normal conditions. See, e.g., U.S. Pat. No. 5,644,352 (Chang), as well as the documents cited therein, for a general discussion of product markers.
One reason that product markers are used is to distinguish genuine goods from counterfeit goods. Unfortunately, counterfeiters have been able to duplicate conventional product markers without too much effort or expense. A product marker provides poor protection against counterfeit goods if counterfeiters can easily misappropriate it. The manner in which counterfeiters have trafficked counterfeit CD-ROM discs is one example of how counterfeiters are able to duplicate markers and thereby circumvent conventional authentication approaches.
Recently, fluorescent compounds have been incorporated into products as latent product markers that can be activated on demand and then detected by visual inspection. Advantageously, these markers are hidden under normal conditions and become visible only when the compounds are exposed to the right kind of radiation, e.g., ultraviolet light. Counterfeiters may not even know that such markers are being used. Consequently, these fluorescent compounds have proven to be excellent product markers. However, to be functional, the compounds must be positioned carefully on a product or its packaging.
Thus, there continues to be a strong demand for an authentication scheme that is difficult for counterfeiters to duplicate and that does not limit marker placement to the surface of a marked product.
Thwarting counterfeiters is not the only reason that manufacturers may desire to mark their products with unique markers. Markers also can be used so that the source of products can be confirmed when the performance of the products, good or bad, becomes an issue. The need for such markers is particularly strong in markets in which products sold by different manufacturers legitimately look similar to each other. For example, plastic container closures such as screw-on beverage bottle caps typically look similar regardless of source. Such closures typically include liners that help provide a good seal when the closure is engaged on a container opening. A manufacturer of closures may purchase liners from more than one manufacturer. Thus, if the seal on some closures fails because of a faulty liner, it may be desirable to determine the manufacturer of the faulty liners. Since liners from different manufacturers look similar, this determination can be difficult.
In such instances, a unique product marker that allows the source of the products at issue to be identified with certainty can be highly desirable. In many of these instances, the marker preferably is hidden so that all of the products visually look the same to the customer, regardless of the manufacturer supplying the goods. Incorporating the marker into the product so as not to affect product performance or to be harmful to the user also is highly desirable.
The present invention provides an improved authentication system and methodology in which an authenticating agent is used as a product marker to help determine the source of products. The authenticating agent includes a substance that forms free radicals upon irradiation. The authenticating agents has a first, latent state that provides a first response to spectroscopic analysis and a second, activated state that provides a second, distinguishable response to spectroscopic analysis. The spectroscopic response of the marker when in the activated, free radical state provides a characteristic xe2x80x9cfingerprintxe2x80x9d associated with genuine goods, but lacking in other goods. Goods incorporating the marker thus may be readily identified and/or distinguished from similar goods originating from another source that lack the marker. Furthermore, because the authenticating agent can be incorporated into the goods in a latent state, it is not a separate, visually identifiable component of the package and is preferably not detectable in its first, latent state, even by spectroscopic means.
In one aspect, the present invention relates to a package including a product that is packaged, at least in part, by a packaging material. The packaging material incorporates an authenticating agent that includes a substance that forms detectable free radicals upon exposure to ionizing radiation. Since preferred methods of analysis do not involve the transmission or reflectance of light, the authenticating agent preferably and advantageously may be incorporated into either or both of the product(s) or packing material(s) without regard to the location, i.e., the agent need not be readily apparent to the unaided eye. In particularly preferred embodiments, the authenticating agent includes an amino acid such as alanine.
A package in accordance with the present invention can be subjected to spectroscopic analysis to determine authenticity or source. Thus, in another aspect, the present invention relates to a method of analyzing a sample to determine whether the sample contains an authenticating agent that forms free radicals upon exposure to ionizing radiation. The method involves irradiating the sample with ionizing radiation and then subjecting the irradiated sample to a spectroscopic analysis effective to provide a spectroscopically derived output indicative of the presence, if any, of free radicals. A determination of whether the sample contains the free radicals is made from information including the spectroscopically derived output of the sample.
In another aspect, the present invention relates to a method of making a package, in which an authenticating agent (as described above) is incorporated into a component of the package as a product marker. The authenticating agent is present in a manner such that the free radicals provide a characteristic spectral response when subjected to a spectroscopic analysis capable of detecting free radicals. The source of the package can be determined from the spectral response.
In yet another aspect, the present invention relates to an authenticating system. The system includes an authenticating agent including a substance that forms free radicals upon irradiation with ionizing radiation. The system further includes reference information derived from data including the spectroscopically derived output resulting from spectroscopic analysis of an irradiated reference sample, wherein the irradiated reference sample includes an amount of free radicals. Also provided is a source of ionizing radiation and a spectroscopic system effective to provide a spectroscopically derived output of a sample to be authenticated wherein the output is indicative of the presence, if any, of the free radicals in the sample to be authenticated.
To assist in understanding the description of the invention that follows, provided immediately below are certain definitions which apply hereinthroughout unless a contrary intention is explicitly indicated:
xe2x80x9cfree radicalxe2x80x9d means a molecular fragment having one or more unpaired electrons, wherein the fragment is formed by splitting a covalent bond;
xe2x80x9cmonomerxe2x80x9d means a single, one unit molecule capable of combination with itself or other monomers to form oligomers or polymers;
xe2x80x9coligomerxe2x80x9d means the polymerization product of 2 to 20 monomers;
xe2x80x9cpolymerxe2x80x9d means the polymerization product of 21 or more monomers and is inclusive of homopolymers, copolymers, and interpolymers as well as blends and modifications thereof;
xe2x80x9cmer unitxe2x80x9d means that portion of a polymer derived from a single monomer; for example, a mer unit derived from ethylene has the general formula (xe2x80x94CH2CH2xe2x80x94);
xe2x80x9chomopolymerxe2x80x9d means a polymer consisting essentially of a single type of repeating mer unit;
xe2x80x9ccopolymerxe2x80x9d means a polymer that includes mer units derived from two monomers and is inclusive of random, block, segmented, graft, etc., copolymers;
xe2x80x9cinterpolymerxe2x80x9d means a polymer that includes mer units derived from at least two monomers and is inclusive of copolymers, terpolymers, tetrapolymers, and the like;
xe2x80x9c(meth)acrylxe2x80x9d means methacryl, acryl, and homologs thereof in which the substituent on the carbon in the alpha position relative to the carboxyl moiety may not only be hydrogen (acryl) or methyl (methacryl), but may also be lower alkyl or cycloalkyl or other suitable monovalent moieties;
xe2x80x9ctransverse directionxe2x80x9d means that direction across a film and perpendicular to the longitudinal direction;
xe2x80x9cfree shrinkxe2x80x9d means the percent dimensional change, as measured by ASTM D 2732, in a 10 cmxc3x9710 cm specimen of film when it is subjected to heat;
as a verb, xe2x80x9claminatexe2x80x9d means to affix or adhere (by means of, for example, adhesive bonding, pressure bonding, corona lamination, and the like) two or more separately made film articles to one another so as to form a multilayer structure, as a noun, xe2x80x9claminatexe2x80x9d means a product produced by the affixing or adhering as just described;
xe2x80x9cdirectly adhered,xe2x80x9d as applied to film layers, means adhesion of the subject film layer to the object film layer, without a tie layer, adhesive, or other layer therebetween.
xe2x80x9cinner layerxe2x80x9d means a layer of a film having each of its principal surfaces directly adhered to one other layer of the film;
xe2x80x9couter layerxe2x80x9d means a layer of a film having less than both of its principal surfaces directly adhered to other layers of the film;
xe2x80x9cbarrier layerxe2x80x9d means a film layer capable of excluding one or more gases (e.g., O2);
xe2x80x9cabuse layerxe2x80x9d means an outer layer and/or an inner layer that resists abrasion, puncture, and other potential causes of reduction of package integrity and/or appearance quality;
xe2x80x9ctie layerxe2x80x9d means an inner layer having the primary purpose of providing interlayer adhesion to adjacent layers that include otherwise non-adhering polymers;
xe2x80x9cbulk layerxe2x80x9d means any layer which has the purpose of increasing the abuse resistance, toughness, modulus, etc., of a multilayer film and generally includes polymers that are inexpensive relative to other polymers in the film which provide some specific purpose unrelated to abuse resistance, modulus, etc.;
xe2x80x9ccomprisingxe2x80x9d is an open-ended term that means that the recited elements are only a part of the product, method or system and that the composition, product, method, system, or the like may include other elements not explicitly mentioned; and
xe2x80x9cseal layerxe2x80x9d (or xe2x80x9csealing layerxe2x80x9d or xe2x80x9cheat seal layerxe2x80x9d or xe2x80x9csealant layerxe2x80x9d) means
(a) with respect to lap-type seals, one or more outer film layer(s) involved in the sealing of the film to itself (in some circumstances, as much as the outer 75 xcexcm of a film can be involved in the sealing of the film to itself or another layer), another film layer of the same or another film, and/or another article which is not a film, or
(b) with respect to fin-type seals, an inside film layer of a package, as well as supporting layers within 75 xcexcm of the inside surface of the innermost layer, involved in the sealing of the film to itself, and as a noun, xe2x80x9csealxe2x80x9d means a bond of a first region of a film surface to a second region of a film surface (or opposing film surfaces) created by heating (e.g., by means of a heated bar, hot air, infrared radiation, ultrasonic sealing, etc.) the regions (or surfaces) to at least their respective softening points so as to cause bonding between polymer chains.